Guilhermino Lúcia, Martins Alexandra, Cunha Sara, Fernandes José O
ICBAS - Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Population Studies, Laboratory of Ecotoxicology and Ecology (ECOTOX), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Research Team of Ecotoxicology, Stress Ecology and Environmental Health (ECOTOX), Portugal.
ICBAS - Institute of Biomedical Sciences of Abel Salazar, University of Porto, Department of Population Studies, Laboratory of Ecotoxicology and Ecology (ECOTOX), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Research Team of Ecotoxicology, Stress Ecology and Environmental Health (ECOTOX), Portugal.
Sci Total Environ. 2021 Aug 25;784:147082. doi: 10.1016/j.scitotenv.2021.147082. Epub 2021 Apr 14.
In many ecosystems, the zooplankton community has been pressured simultaneously by microplastic pollution and alterations resulting from global climate changes. The potential influence of light intensity rise (from 10,830 lx to 26,000 lx) and water temperature rise (from 20 °C to 25 °C) on the long term-toxicity of microplastics (MPs) to Daphnia magna were investigated. Three 21-day laboratory bioassays with model MPs (1-5 μm diameter) were carried out at (i) 20 °C/10830 lx, (ii) 20 °C/26000 lx, and (iii) 25 °C/10830 lx. In each bioassay, one control (no MPs) and three MP concentrations (0.04, 0.09, 0.19 mg/L) were tested. In all the bioassays, MPs caused parental and juvenile mortality, and reduced the somatic growth, reproduction and population growth rate. The MP ECs on living offspring (95% confidence interval within brackets) were 0.146 mg/L (0.142-0.151 mg/L) at 20 °C/10830 lx, 0.102 mg/L (0.099-0.105 mg/L) at 20 °C/26000 lx, and 0.101 mg/L (0.098-0.104 mg/L) at 25 °C/10830 lx. Relatively to the respective control group, 0.19 mg/L of MPs decreased the mean of the population growth rate by 27% at 20 °C/10830 lx, 38% at 20 °C/26000 lx and 59% at 25 °C/10830 lx. Based on the population growth rate and in relation to 20 °C/10830 lx (control, no MPs), the interaction between increased light intensity (26,000 lx) and MPs was synergism (at all the MP concentrations tested). The interaction between water temperature rise (25 °C) and MPs was antagonism at 0.04 mg/L of MPs and synergism at 0.09 and 0.19 mg/L of MPs. In the present scenario of climate changes and global MP pollution such findings raise high concern because zooplankton communities are crucial for aquatic biodiversity conservation, ecosystem functioning and services provided to humans. Further studies on the combined effects of MPs, other common pollutants, and alterations due to climate changes are needed.
在许多生态系统中，浮游动物群落同时受到微塑料污染和全球气候变化导致的环境变化的压力。研究了光照强度升高（从10830勒克斯升至26000勒克斯）和水温升高（从20℃升至25℃）对微塑料（MPs）对大型溞长期毒性的潜在影响。使用模型微塑料（直径1 - 5微米）进行了三项为期21天的实验室生物测定，分别在（i）20℃/10830勒克斯、（ii）20℃/26000勒克斯和（iii）25℃/10830勒克斯条件下进行。在每项生物测定中，测试了一个对照组（无微塑料）和三个微塑料浓度（0.04、0.09、0.19毫克/升）。在所有生物测定中，微塑料导致亲代和幼体死亡，并降低了体细胞生长、繁殖和种群增长率。在20℃/10830勒克斯条件下，对存活后代的微塑料半数效应浓度（括号内为95%置信区间）为0.146毫克/升（0.142 - 0.151毫克/升），在20℃/26000勒克斯条件下为0.102毫克/升（0.099 - 0.105毫克/升），在25℃/10830勒克斯条件下为0.101毫克/升（0.098 - 0.104毫克/升）。相对于各自的对照组，0.19毫克/升的微塑料在20℃/10830勒克斯条件下使种群增长率平均值降低了27%，在20℃/26000勒克斯条件下降低了38%，在25℃/10830勒克斯条件下降低了59%。基于种群增长率并相对于20℃/10830勒克斯（对照组，无微塑料），光照强度增加（26000勒克斯）与微塑料之间的相互作用是协同作用（在所有测试的微塑料浓度下）。水温升高（25℃）与微塑料之间的相互作用在微塑料浓度为0.04毫克/升时为拮抗作用，在微塑料浓度为0.09和0.19毫克/升时为协同作用。在当前气候变化和全球微塑料污染的情况下，这些发现引发了高度关注，因为浮游动物群落对于水生生物多样性保护、生态系统功能以及为人类提供的生态系统服务至关重要。需要进一步研究微塑料、其他常见污染物以及气候变化引起的环境变化的综合影响。
